PSI - Issue 18

Abdeljalil Jikal et al. / Procedia Structural Integrity 18 (2019) 731–741 Abdeljalil JIKAL et al. / Structural Integrity Procedia 00 (2019) 000–000

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4

illustrated in Fig. 1, at ambient conditions of air and temperature in the laboratory. The strand specimen was fixed between two clamps by means of wedges screwed at both ends of the strand to prevent any sliding of the specimens during the test. The mobile cylinder of the machine moves with a constant velocity until the breaking of the sample ISO (1974).

Fig. 1. (a) Samples after corrosion damage; (b) Mounting the strand sample in the Zwick Roell tensile machine.

3. Theory 3.1. Rupture force theories

A formula that integrates the ultimate stresses, the inner and outer diameters of a tube Eq. 1 was developed by Faupel et al (1953). Klever (2006) developed a formula based on thickness, average diameter and ultimate stress. Brabin (2009) then presented a new formula using the same data as Faupel in addition to a parameter, which is related to the characteristics of the studied material Veritas (2000).

0 2 ln          u i    y D D   

2

(1)





P

y

3

In our work, we put the following equation:

(2)

P F S 

Therefore, we have

 

   



  



D

2

y

t

(3)







F

S

2

ln    

y



n D

3

u

f

f

3.2. Static damage The static damage model is based on monitoring the evolution of the ultimate residual force, which depends on the level of damage. It is expressed by the following relationship Mouhib (2015).

F

ur u

1 F D F F    1 s

(4)

u u